Expanded junction tube repairs



United States Patent 72] lnventor Richard Henry Evans [56] References Cited Fmham, England UNITED STATES PATENTS Eff; 22 2,034,717 3/1936 Duram 122/235 9 Patented Dec. 1970 2,411,246 1 1/1946 Clapper 29/l57.4 73 Assignee b k & Wi Limited Primary Examiner-Kenneth W. Sprague London, England Atrorne \'J. Maguire a corporation of Great Britain [32] Priority Apr. 23, 1968 Great Britain ABSTRACT: A method and apparatus for the repair of [31] 19086/68 damaged tubes in a vapor generator which includes removing the damaged portion of tube and connecting the remaining tube sections through a junction member or, when re uired, [54] TUBE REPMRS adding a replacement tube portion and connecting ea h end g through a junction member to a corresponding one of the [52] U.S.Cl 122/235, remaining tube sections. The junction member is provided 122/360; 29/157.4 with an access opening and is fitted with two tubular stubs, [51 Int. Cl F 22b 37/00 each arranged to receive a tube end. A tool may be introduced [50] Field of Search 122/235, through the access opening to expand each tube end into its 360, 361, 365; 29/l57.4; 285/(Inquired) corresponding stub.

PATENIEn nficzslsm 3.550.561

- sum 2 UF 3 AT RNEY PATENATEDQEZQ SHEET 3 OF 3 Y Has FIG. I2

EXPANDED JUNCTION TUBE REPAIRS This invention relates to tube walls and to tubes that may be used in tube walls. 7

When a boiler is installed in a ship, it may happen that a fault occurs in one of the boiler tubes while the ship is at sea. In some forms of boiler, it may be adequate simply to plug the faulty tube and leave it inoperative until the ship reaches port and a proper repair can be effected. Such a procedure is, however, inadequate when the boiler walls are of the kind in which the spaces between parallel tubes are closed by webs so that the wall itself is gastight.

An object of the invention is to enable a reliable repair to be effected to a tube with comparatively simple equipment, and a particular application is to a wall forming part of the boundaries of the furnace chamber or other gas space of a marine boiler. I

According to the present invention, there is provided a tube including two parts connected together by a junction member through which fluid may flow from one part to the other, wherein the junction member includes a body portion and two tubular stubs each of the stubs receives an end of one of the parts, the end is expanded to form a joint with the stub, and the junction member has one or more openings each closed by a closure member, the opening or openings being such that, were the closure member or members removed, the opening or openings would provide access through which an expanding tool could be inserted into, and removed from the junction member and operated to effect expansion of one of the ends into its associated stub.

According to the present invention, there is also provided in a tube wall forming part of the boundary of a gas space, three spaced parallel tubes of which the central tube includes a first outer part, a central part, and a second outer part, a first junction member connecting the first outer part to the central part so that fluid may flow through the junction member between the parts, and a second junction member connecting the second outer part to the central part so that fluid may flow through the junction member between the parts, wherein each includes a body portion and two tubular stubs, each of the stubs receives an end of one of the parts that are connected together by the junction member, the end is expanded to form a joint with the stub, the junction member has one or more openings each closed by a closure member, the or each, opening is such that were the corresponding closure member removed, the or each opening would provide access through which an expanding too'l could be inserted into, and removed from, the junction member and operated to effect expansion of one, at least, of the ends into its associated stub, and the, or each, closure member lies outwardly of the gas space.

In the accompanying drawings which illustrate, by way of example, embodiments of the present invention:

FIG. I shows three parallel upright tubes where two parts of the central tube are joined by a junction member with parts of the internal structure omitted for sake of clarity and in which the upper and lower halves indicate different schemes whereas in practice both halves would be identical;

FIG. IA shows an isometric view of the top half of the junction member of FIG. 1;

FIG. 1B shows an isometric view of the bottom half of the junction member of FIG. 1;

FIG. 2 shows a side elevation of the central tube of FIG. 1 with the junction member in section and also shows part of the closure member by which an opening in the junction member is closed in section;

FIG. 3 shows a plan view from III-III of FIG. 1 and also shows the closure member by which an opening in the junction member is closed in section;

FIG. 4 shows a view in the direction of the arrow IV of FIG. 1;

FIG. 5 shows a method of repairing the central tube of three parallel upright tubes where the spaces between the tubes are closed by webs; I

FIG. 6 shows the side elevation of two parts of a tube joined by another form of junction member shown in section where each closure member is in the form of a thimble;

FIG. 7 is a plan view of junction member shown in FIG. 6;

FIG. 8 shows in sections a junction member somewhat similar to that of FIG. 6 but modified in structure;

FIG. 9 shows the side elevation of two parts of the central tube of three parallel upright tubes joined by another form of junction member, shown in part section, and using a closure member in the form of a thimble;

FIG. 10 shows a plan view of FIG. 9, including the other tubes, with a part section of the junction member on X-X;

FIG. 11 shows a side elevation of two parts of a tube connected by a form of junction member that is a modification of what is shown in FIG. 9; and

FIG. 12 shows the junction member of FIG. 11 in section and shows the change in structure from that shown in FIG. 9 designed for improved water circulation.

The three parallel tubes A, A, A, shown in FIG. 1 are included in a panel of tubes, similar to the tubes A, forming part of the boundary of a gas space, where each tube in the panel is spaced from the next by a substantially uniform separation. The spaces between the tubes are closed by webs in the form of strips each welded along its opposite edges to two adjacent tubes.

The form of junction member shown in FIGS; 1, 2, 3 and 4 is of hollow construction with a stub 1 at each end, the axes of the stubs being in alignment. The inner diameters of the walls 2 stubs are just greater than the outer diameters of the parts that they receive and the thickness of the wall 2 is less than the separation between either of the adjacent tubes. The inner face 3 of the wall 2 of each stub is provided with two annular grooves 4 to facilitate the formation of an hermetic joint when the tube end 5 is expanded into it. The stubs have an extension part 6 which has an outer diameter equal to that of the wall 2 and an inner diameter slightly greater than that of the wall 2.

The body 7 of the junction member includes a half cylinder 8 connected at each end to the extension parts 6 of the stubs having its axis on the axis of the stubs and outer and, inner diameters equal to those of the extension parts 6 of the stubs.

The sides of the half cylinder 8 are connected to sidewalls 9 which run the length of the half cylinder and are perpendicular to the plane containing its axis and sides. The central parts of the walls 9 are connected to walls 10 which extend outwardly from the plane of the walls 9. Walls 11, which extend parallel to walls 9 are connected to walls 10 and are joined by a front wall 12. Walls 10, 11 and 12, are joined at the top and bottom by walls 13 and 14.

The end parts of the walls 9 join on to top'and bottom walls, 15, 16 of semicircular cross section which slope downwardly and upwardly, respectively between the extension parts 6 and the walls 13 and 14. In one version represented by the bottom half of FIG. 1, the top and bottom walls are connected to the walls 13 and 14; in the other version, represented by the top half of FIG. 1, they slope on to the front wall 12.

There is thus formed an enlargement 17 projecting to one side of the stubs and a square opening 18 is provided in the front wall. An expanding tool is inserted through the opening 18 into a tube end 5 received by a stub 1.

To close the opening, a handhole fitting assembly 20 comprising a cap 21a and a stem 21b forming a clamp 21, bridge 22 and nut a nut 23, is used. The cap 21a is of larger cross section than the opening and carries a sealing band 24 around the shoulder 25 of the cap and is of such dimensions as to form a close fit within the opening. The inner edges of the cap are rounded so that it can be positioned within the junction member by passing it diagonally through the opening and then twisting it. The bridge 22 is then slipped over the clamp and nut 23 screwed on to the stem 21b to force the bridge against the outer face 26 of the front wall and so enclose the sealing band 24 between the inner face 27 of the front wall and the shoulder of the cap.

In the version of the junction member represented by the upper half of FIG. 1 an opening 19 is provided in the top wall 15. This opening permits the passage of means by which the expansion tool that fits into the bottom part of the tube could be operated, said means being connected to the tool within the junction member by a universal coupling. A similar hole is provided in the bottom wall by which the expansion tool in the upper part of the tube could be operated. These latter openings can be closed by means of a bolt, nut and washer.

In the version of the junction member represented by the lower half of FIG. 1 the expansion of a tube in either of the stubs could be effected from opening 18, the expansion tool being actuated by a lever passing through the opening. The enlargement is of such dimensions that the opening permits the lever to swing through 30 and with this swing and a ratchet connection between the lever and the corresponding tool, the appropriate expansion of a tube end can be effected quickly. Thus the access by which the expansion tool is inserted and operated is provided by a single opening whereas in the other version more than one opening is necessary to provide this ac- :ess.

To effect the repair to the tube A shown in FIG. 1 the boiler is first put out of action and the tubes allowed to cool down. The faulty piece of tube 28, FIG. 5, is cut out leaving a first outer part 29 and a second outer part 30. The portions of the webs 31 at the end of the faulty piece of tube are removed together with the portion of the webs 31 at the adjacent ends of the outer parts. The web 32 is left intact, however, over the center of the gap 33 between the outer parts of the tube; the lengths of the parts of the webs that are cut out are such as to allow the junction pieces to be manipulated and what lengths are necessary for this will be apparent from the description that follows.

A first junction member 34 is brought into the gap with one of the stubs la fitting over the upper end 35 of the lower outer part 30 and the opening, or openings, lying outwardly of the gas pass.

A conventional expanding tool is then introduced into tube end 35 and, with the stubs aligned with the general direction of the axis of the tube under repair, the end 35 is expanded to fonn a hermetic seal with stub 1a by the operation of a lever connected with the expanding tool through stub 1b.

A length of tube 36, that will form the central part of the tube when it has been repaired and has the same inner and outer diameters as the outer parts of the tube, is then introduced into stub 1b and pushed into the junction member to leave gap 37 between the upper end 41 of the central part and the lower end 38 of the upper outer part that is wide enough to receive second junction member 39. The second junction member, which is similar to the first, is introduced into the gap 37 and raised until the lower end 38 of the upper outer part lies in stub of the junction member. With the stubs aligned with the general direction of the axis of the tube under repair, end 38 is expanded into stub 10 through the access provided by stub 1d.

The central part 36 is then raised to the position in which its end 40 lies in stub 1b of junction member 34 and the other end 41 lies in stub 1d of junction member 39. The ends are then expanded through the access provided by the openings in the corresponding junction members and the openings are subsequently closed. It will be realized that with this procedure the parts of the web that remain on the outer parts of the tube are coincident with the stubs la and 1c of the junction members when the junction members are in their final positions.

Modifications of this procedure are envisaged. For instance, the second junction member 39 could be fixed to the central part 36 before being fixed to the upper outer part 38.

Again after junction member 34 has been fixed to the outer part 35, the junction member 39 may be slid onto the outer part 38 to an extent sufficient to provide a gap between the two junction members into which the central part 36 can be introduced. The expansion at end lb of junction member 34 can then be effected and, subsequently, the two expansions at the ends 16. Id of junction member 39, both the latter expansions being effected through access provided by an opening, or openings in the junction member. A disadvantage of this procedure is that to permit movement of junction member 39 along the outer part 38 the webs 42 between the outer part 38 and the adjacent tubes 43 must be cut away to a greater depth but the procedure might be preferred if the central part 36 were short or curved over such a proportion of its length that the straight end portions 40, 41 were too short to receive, or be received by, a junction member.

Again the procedures could be reversed with junction member 39 being dealt with as for 34 and vice versa.

An advantage of the use of two junction members in this way lies in the fact that it allows junction members ofa standard size to be used with a great range of distance between the outer parts, the different distances being accommodated by different lengths of the central part of the tube. Moreover, the central part could be curved so that should a fault occur at a bend of a tube, at the corner of a gas pass, for instance, the bent portion of the tube can be replaced by the use of a junction member on each side of the bend.

If the length of the faulty piece of tube is less than the separation between the stubs of a junction member then a single junction member can be used. In this case, the faulty piece is cut out together with the webs that extend along its sides. The parts of the webs at the facing ends of the remaining parts of the tube are removed to accommodate the stubs of the junction member and a slit is effected between one of the parts and the webs at each side of the part, for some distance back from the end, to enable that end of the part to be sprung out of the wall. One stub of the junction member can then be slipped on to the outwardly sprung part to an extent that allows the part to return to its original position when the junction member can be slid towards the other part until the end of the other part lies in the other stub of the junction member. The necessary expansion can be effected through the access provided by the opening or openings formed in the junction member. It is envisaged that the junction member might not return to a position in which the stubs are precisely aligned with the wall axis of the tube and the tube parts that are connected together by it curve slightly outwardly into the junction member from ends that lie in the wall.

In a modified form of the junction member shown in FIGS. 1-4 the portion 8 is replaced by an arcuate portion that subtends less than and wall 10 and the central part of wall 9 are combined in a wall that diverges outwardly from the arcuate portion.

The forms ofjunction member shown in FIGS. 6-I2 also have, as in the form shown in FIGS. l4, two stubs and axes aligned and a half cylinder, connected between the extension parts of the stubs, forming part of the body of the junction member.

In the junction member shown in FIGS. 6 and 7 the sides of the half cylinder 44 are connected to sidewalls that extend along the length of the half cylinder and are inclined outwards from it to meet the sides of the half cylinder 45. The sidewalls also extend along the length of half cylinder 45 to form the enlargement.

Top and bottom walls 46, 47 enclose the space between the sidewalls, half cylinder 45 and extension parts of the stubs. The top wall 46 contains circular opening 48 that provides access for effecting expansion between tube end 50 and stub 51. The bottom wall 47 contains circular opening 49 that provides access for effecting expansion between tube end 52 and stub 53. The internal diameter of the half cylinder 45 is greater than the diameter of each opening.

The radii of the internal edges 55, 56 of the walls 46, 47 are the same as the internal radii of the extension parts of the stubs. The outside of the sidewalls have strengthening portions 57 so that the sidewalls will withstand the pressure in the junction member when water flows through.

In the version of the junction member shown in FIG. 8 the axes of the circular openings 58, 59 are inclined inwardly at an angle to the axis of the stubs so that outer parts of the top and bottom walls, 60, 61 of the enlargement incline downwardly and upwardly, respectively, from the edges 62, 63 of the extension parts of the stubs. The wall 60 is connected to a half cylinder 64 the axis of which is the same as that of the opening 58. Similarly wall 61 is connected to half cylinder 65 lying on the same axis as opening 59. The half cylinders 64, 65 thus incline inwardly and are joined at the central plane of the junction member that is perpendicular to the axes of the stubs. The opening 58 provides access for effecting expansion between tube end 58a and its associated stub. The opening 59 provides access for effecting expansion between tube end 59a and its associated stub.

Sidewalls are connected to the sides of the half cylinder 66 and extend along the length of half cylinder. The gaps between the extension parts of the stubs and the sidewalls are enclosed by the inner parts of the top and bottom walls 60, 61. The top and bottom parts of the sidewalls than incline downwardly and upwardly respectively, along the edges of the outer parts of the walls 60 and 61 to meet the sides of the half cylinders 64, 65. The sidewalls have strengthening portions to withstand the pressure in the junction member when water flows through.

The main advantage of this type of junction member compared to the fonn shown in FIGS. 6 and 7 is that the area of the sidewall is reduced so that the junction member is lighter. Also the openings, being at an angle to the axis of the stubs, provide a clearer view of when inserting each expansion tool and make it easier to insert the means of operating each expansion tool.

In the junction member shown in FIGS. 9 and the half cylinder 67 forming part of the body of the junction member connects on to sidewalls 68 and 69. Each sidewall has a first portion 70, which connects on to the sides of .the half cylinder and extends along the length of the half cylinder, and a second portion 71 which is a flat semicircular surface inclining outwardly to meet the wall 72.

The wall 72 is of circular cross section with its axis perpendicular to that of the stubs and is connected to the front wall 73. A circular opening is provided in the front wall 73. The diameter of the internal surface 74 of the wall 72 is greater than the diameter of the opening. The side surfaces 75, 76 of the wall 72 are connected to the edges of the flat surfaces 71. The top and bottom edges-77, 78 of the wall 72 are joined to the ends 79, 80 of the extensions of the stubs and the top and bottom surfaces of the wall 72 curve round the edges of the extensions to join on to the sidewalls 68, 69.

In the junction member shown in FIGS. 11 and 12 the enlargement 81 is formed by the portion 82 and the walls 83, 86, 87 88 and 90. The portion 82 is of circular cross section with its axis perpendicular to the axis of the-stubs and is connected to the front wall 83. A circular opening is provided in the front wall 83. The top and bottom surfaces 84,85 of the portion 82 join on to top and bottom walls 86, 87, which are of semicircular cross section and incline upwardly and downwardly respectively, to join on to the extensions of the stubs. Each side of the top and bottom walls 86, 87, is connected to a flat wall 88 which is also connected to the portion 82 and to the side of the half cylinder 89 which forms part of the body of the junction member. Each side surface of the portion 82 is connected to the edges of a flat semicircular wall 90 which inclines inwardly and is connected to one side of the half cylinder 89.

The main advantage of this type of junction member over that shown in FIGS. 9 and 10 is that the top and bottom walls 86, 87 of the enlargement provide an improved water flow path for cooling the closure member. This type of enlargement compared with that shown-in FIGS. 9 and 10, also makes it easier to insert the expansion tool and the means of operating the expansion tool.

The type of closure member shown in FIGS. 6-12 is in the form of a thimble joined, at its open end, to the opening by expansion and cooled by the water flowing through the tube. The face of each opening contains two annular grooves to facilitate the formation of an hermetic joint when the closure member is expanded into the opening. A particular advantage of this type of closure member is in such applications where use of the handhole fitting assembly would cause the latter to overheat.

In an alternative form of the panel of tubes'the webs are in the form of fins projecting towards each other from adjacent tubes and welded together along their adjoining edges.

A characteristic of all the ways of using the junction members is that all the joints are effected by expansion alone. No welding is required so that effecting tube repairs in the manner described is especially attractive on board ship where the necessary welding skill may not be available. The apparatus that is required is provided by a stock of junction members, tubes, cutting apparatus, and expanding tools.

It is envisaged that in the repair of the tube wall as described with reference to FIG. 5 the part 36 may not have exactly the same inner diameter as the outer parts of the tube. A length of tube that has substantially the same inner diameter as that of the outer parts, so that is has a wall thickness adequate for the pressure of the expansions, could be used.

lclaim:

1. A tube having two sections connected by a junction member for fluid flow therethrough wherein the junction member includes a body portion, two tubular stubs extending from the body portion, each of the stubs arranged to receive an end of one of the tube sections, means for expanding said end to form a joint with the stub, means defining at least one opening in the junction member, a removable closure member associated with the opening, and said opening being dimensioned to provide access for the expansion means to effect expansion of one of said tube ends into its respective stub.

2. A tube according to claim 1 wherein said second named means defines a single opening in the junction member, the opening being dimensioned to provide access for the expansion means to effect expansion of each of the tube ends into its respective stub.

3. A tube according to claim 1 wherein the tube and junction member arrangement is included in a plurality of spaced parallel tubes forming a tube wall anddefining part of a gas passage boundary and said closure member lies outwardly of the gas passage.

4. A tube wall forming part of a gas passage boundary and having at least three spaced parallel tubes in coplanar alignment wherein the central tube comprises a first and second outer section and an intermediate section, a first junction member connecting the first and intermediate sections and a second junction member connecting the second and intermediate sections, said sections being thus connected for fluid flow therethrough, each of the junction members including a body portion, two tubular stubs extending from the junction member, each of the stubs arranged to receive an end of one of the tube sections, means for expanding said end to form a joint with the stub, means defining at least one opening in the junction member, a removable closure member associated with the opening and lying outwardly of the gas passage, and said opening being dimensioned to provide access for the expansion means to effect expansion of one of the tube ends into its respective stub.

5. A tube wall according to claim 4 wherein said secondnamed means defines a single opening in the junction member, the opening being dimensioned to provide access for the expansion means to effect expansion of each of the tube ends into its respective stub.

6. A tube wall according to claim 4 wherein said parallel tubes are uniformally spaced from each other.

7. A tube wall according to claim 4 wherein said parallel tubes include web extensions enclosing the spacing between adjacent tubes.

8. A tube according to claim 1 wherein the stubs of said junction member have a common axis, the junction member wall portion lying on the side of the plane of said axis and extending between the outer ends of the stubs being of arcuate cross section, the junction member wall portion lying on the opposite side of said plane and extending between the inner ends of the stubs including a hollow enlargement projecting beyond the face of the stubs, said second-named means defining at least one opening in the hollow enlargement.

9. A tube according to claim 8 wherein the portion of junction member wall having an arcuate cross section is of semicircular cross section.

10. A tube according to claim 8 wherein the hollow arrangement includes a wall parallel to the plane of the stub axis and the second-named means defines a single opening in said wall of the hollow enlargement.

11. A tube according to claim 8 wherein the second-named means defines two openings having a common axis parallel to the axis of the stubs.

12. A tube according to claim 9 wherein the second-named means defines two openings, each of said openings having its axis inclined in the direction of the stub axis, and the axes of said openings intersecting at a point along a plane drawn across the center of the junction member and perpendicular to the axis of the stubs.

13. A tube according to claim 10 wherein the closure member associated with said opening is in the form of a cap and lies within the junction member, the cap being dimensioned to fit through the opening and being held in a closing position by means including an outwardly extending stem, a nut threaded on the stem and reacting against the junction member.

14. A tube according to claim 11 wherein the closure member associated with each of said openings is in the form of a thimble, said thimble fitting within the respective opening with its open end facing outwardly and being held in a closing position by expansion.

15. A method of connecting two sections of a tube for fluid flow therethrough and including a junction member, two tubular stubs extending from the junction member, means defining at least one opening through said junction member, the steps comprising:

inserting an end of one of the tube sections into one of the stubs;

expanding said tube end into said stub;

inserting an end of the other tube section into the other stub; and

expanding said other tube end into said other stub through said opening.

16. A method of forming a tube wall including a plurality of parallel tubes, a junction member, two tubular stubs extending from the junction member, means defining at least one opening through said junction member, the steps comprising:

removing an intermediate portion of one of said tubes;

springing one of the remaining sections of said tube; inserting an end of said sprung section into one of the stubs; moving the junction member along the sprung section; returning the sprung section to its original position;

moving the junction member to receive an end of the other remaining section;

inserting said end of said other remaining section into said other stub of the junction member; and

expanding said ends of said remaining sections into corresponding stubs through said opening,

17. A method of forming a tube wall including at least three spaced parallel tubes, two junction members, two tubular stubs extending from each of the junction members, means defining at least one opening through each of the junction members, the steps comprising:

removing two intermediate portions of the central one of said tubes;

inserting an end of one of the remaining outer sections of said tube into one of the stubs of one of the junction members;

expanding said tube end into said stub;

inserting an end of the remaining center section of said tube into the other stub of said junction member;

moving the end of said center section into said junction member until a gap exists between the other end of the center section and the end of the adjacent outer section; introducing the other junction member into said gap; inserting an end of the other remaining outer section into one of the stubs of said othe gjunction member; expanding the tube end of sax other outer section into the stub of said other junction member;

moving said center section until each tube end is inserted into a corresponding stub; and

expanding each tube end of said center section into its corresponding stub.

18. A method of forming a tube wall including at least three spaced parallel tubes, two junction members, two tubular stubs extending from each of the junction members, means defining at least one opening through each of the junction members, the steps comprising:

removing two intermediate portions of the central one of said tubes;

inserting an end of one of the remaining outer sections of said tube into one of the stubs of one of the junction members; expanding said tube end into said stub; inserting an end of the other remaining outer section of said tube into one of the stubs of said other junction member;

moving said other junction member along said other outer section until a gap exists between the junction members to accommodate the center section;

inserting an end of the center section of said tube into the other stub of said junction member;

expanding the end of said center section into said other stub;

moving the other junction member to receive the other end of said center section;

inserting said other end of the center section into the other stub of said other junction member; and

expanding each of the tube ends inserted in said other junction member into its corresponding stub. 

